Bodies made of ceramic material, activated carbon, and zeolite are used in a variety of applications such as catalytic or substrates for catalysts, adsorption of hydrocarbons and other impurities from gas streams (frequently air) and liquids, etc.
One common method of making these bodies is by shaping a plasticized mixture of the respective powders, binders, etc. carried in a vehicle. Normally, the vehicle is water. The shaped bodies are dried and often heat-treated. If the powders have a very high surface area, which is most often the case with activated carbon and molecular sieve particularly zeolite, and when water is the vehicle, a very large amount of water is needed to adequately wet the powders and binders. Hence, the drying time can be very long, e.g., normally about 4 days at about 95.degree. C. for bodies made of activated carbon. The long drying time is needed to prevent rapid loss of a large amount of water which results in non-uniform shrinking and cracking in the body, thus undermining its strength, length of life, and catalytic and adsorption properties.
Therefore, it would be advantageous to be able to accomplish drying in a shorter time and at the same time avoid non-uniform shrinking and cracks and preserve properties of strength, life and adsorption and catalytic properties.
The present invention provides a method of forming these bodies which achieves these results.